Automotive Electric Motor Coil Wire Bending for Braid Wire Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Automotive electric motors with mechanical commutation face reliability and manufacturing cost issues due to damage from burrs and sharp edges on stiff coil wire ends, which can sever flexible braid wires, leading to motor failure and increased manufacturing complexity.
Innovation Solution
The coil wire end is bent away from the braid wire to prevent contact with sharp edges, and the braid wire is welded to an axial section of the coil wire, reducing the risk of damage and eliminating the need for deburring, with a preferred bending angle of 60°-120° and a welding area orthogonal to the coil wire's longitudinal direction, and the coil wire end can be inserted into a pocket to further reduce stress on the connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coil wire end is left straight after cutting, then the manufacturing process is simple, but the sharp edge and burr can damage the braid wire leading to motor failure
Solution Approach 1:
The coil wire end is bent into a curved configuration at an angle of 45° to 90° relative to the wire axis, transforming the sharp linear edge into a curved surface that does not concentrate stress on the braid wire connection point, thereby preventing damage while maintaining manufacturing simplicity
Solution Approach 2:
The wire end is bent asymmetrically at a specific angle range (45°-90°) rather than remaining symmetric and straight, creating an orientation that spatially separates the cut edge from the braid wire connection area, eliminating the harmful sharp edge effect without requiring complex symmetric structures
2Reliability
If additional manufacturing steps are added to remove burrs and sharp edges, then the braid wire damage is prevented, but the manufacturing costs increase
Solution Approach 1:
The wire end is bent during the standard cutting process itself, performing the protective action of edge removal in advance as part of the normal manufacturing flow, eliminating the need for separate deburring operations and associated costs
Solution Approach 2:
The wire end geometry is changed by bending it at a specific angle (45°-90°), transforming the problematic sharp edge parameter into a protective curved surface, achieving burr-free operation through geometric transformation rather than material removal processes
3Ease of manufacture
If the wire end surface faces the braid wire, then the welding portion is accessible, but the sharp edge can sever the braid wire during operation
Solution Approach 1:
The wire end is bent in a direction perpendicular to the original wire axis, moving the cut edge into a different spatial dimension that is offset from the braid wire connection plane, allowing welding access while preventing edge contact with the braid wire during operation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances the reliability and longevity of the automotive electric motor by preventing braid wire damage and reducing manufacturing costs by eliminating deburring steps, while also minimizing electromagnetic interference and maintaining mechanical integrity.
Implementation Method 1
The braid wire is provided with a wire end, which is electrically and mechanically connected to the coil wire by welding
Data Source
Figure 1~2
AI summary
The automotive electric motor (10) with mechanical commutation comprises a stiff coil wire (58) with a welding portion (66) and an end portion (70) adjacent to the welding portion (66), and a flexible braid wire (54) with a wire end (62), the wire end (62) being electrically and mechanically connected to the coil wire (58) at the welding portion (66) by welding. The end portion (70) of the coil wire (58) is bended in relation to the welding portion (66) and is thereby bended away from the braid wire (54) so that an end surface (78) of the end portion (70) of the coil wire (58) is not facing the braid wire (54).